US9908215B1 - Systems, methods and assemblies for processing superabrasive materials - Google Patents

Abstract

A method of processing a polycrystalline diamond material includes exposing at least a portion of a polycrystalline diamond material to a processing agent for processing at least a portion of the polycrystalline diamond material. The method further includes applying a body force to the volume of processing agent while at least the portion of the polycrystalline diamond material is exposed to the processing agent, and heating at least one of the processing agent and at least the portion of the polycrystalline diamond material exposed to the processing agent during application of the body force to the processing agent.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 62/036,613, titled “SYSTEMS, METHODS AND ASSEMBLIES FOR PROCESSING SUPERABRASIVE MATERIALS” and filed 12 Aug. 2014, the disclosure of which is incorporated, in its entirety, by this reference.

BACKGROUND

Wear-resistant, superabrasive materials are traditionally utilized for a variety of mechanical applications. For example, polycrystalline diamond (“PCD”) materials are often used in drilling tools (e.g., cutting elements, gage trimmers, etc.), machining equipment, bearing apparatuses, wire-drawing machinery, and in other mechanical systems.

Conventional superabrasive materials have found utility as superabrasive cutting elements in rotary drill bits, such as roller cone drill bits and fixed-cutter drill bits. A conventional cutting element typically includes a superabrasive layer or table, such as a PCD table. The PCD table is formed and bonded to a substrate using an ultra-high pressure, ultra-high temperature (“HPHT”) process. The cutting element may be brazed, press-fit, or otherwise secured into a preformed pocket, socket, or other receptacle formed in the rotary drill bit. In another configuration, the substrate may be brazed or otherwise joined to an attachment member such as a stud or a cylindrical backing. Generally, a rotary drill bit may include one or more PCD cutting elements affixed to a bit body of the rotary drill bit.

Conventional superabrasive materials have also found utility as bearing elements in thrust bearing and radial bearing apparatuses. A conventional bearing element typically includes a superabrasive layer or table, such as a PCD table, bonded to a substrate. One or more bearing elements may be mounted to a bearing rotor or stator by press-fitting, brazing, or through other suitable methods of attachment. Typically, bearing elements mounted to a bearing rotor have superabrasive faces configured to contact corresponding superabrasive faces of bearing elements mounted to an adjacent bearing stator.

Superabrasive elements having a PCD table are typically fabricated by placing a cemented carbide substrate, such as a cobalt-cemented tungsten carbide substrate, into a container or cartridge with a volume of diamond particles positioned on a surface of the cemented carbide substrate. A number of such cartridges may be loaded into a HPHT press. The substrates and diamond particles may then be processed under HPHT conditions in the presence of a catalyst material that causes the diamond particles to bond to one another to form a diamond table having a matrix of bonded diamond crystals. The catalyst material is often a metal-solvent catalyst, such as cobalt, nickel, and/or iron that facilitates intergrowth and bonding of the diamond crystals.

In one conventional approach, a constituent of the cemented-carbide substrate, such as cobalt from a cobalt-cemented tungsten carbide substrate, liquefies and sweeps from a region adjacent to the volume of diamond particles into interstitial regions between the diamond particles during the HPHT process. In this example, the cobalt acts as a catalyst to facilitate the formation of bonded diamond crystals. Optionally, a metal-solvent catalyst may be mixed with diamond particles prior to subjecting the diamond particles and substrate to the HPHT process. The metal-solvent catalyst may dissolve carbon from the diamond particles and portions of the diamond particles that graphitize due to the high temperatures used in the HPHT process. The solubility of the stable diamond phase in the metal-solvent catalyst may be lower than that of the metastable graphite phase under HPHT conditions. As a result of the solubility difference, the graphite tends to dissolve into the metal-solvent catalyst and the diamond tends to deposit onto existing diamond particles to form diamond-to-diamond bonds. Accordingly, diamond grains may become mutually bonded to form a matrix of polycrystalline diamond, with interstitial regions defined between the bonded diamond grains being occupied by the metal-solvent catalyst.

In addition to dissolving diamond and graphite, the metal-solvent catalyst may also carry tungsten and/or tungsten carbide from the substrate into the PCD layer. Following HPHT sintering, the tungsten and/or tungsten carbide may remain in interstitial regions defined between the bonded diamond grains.

The presence of the solvent catalyst in the diamond table may reduce the thermal stability of the diamond table at elevated temperatures. For example, the difference in thermal expansion coefficient between the diamond grains and the solvent catalyst is believed to lead to chipping or cracking in the PCD table of a cutting element during drilling or cutting operations. The chipping or cracking in the PCD table may degrade the mechanical properties of the cutting element or lead to failure of the cutting element. Additionally, at high temperatures, diamond grains may undergo a chemical breakdown or back-conversion in the presence of the metal-solvent catalyst. At extremely high temperatures, portions of diamond grains may transform to carbon monoxide, carbon dioxide, graphite, or combinations thereof, thereby degrading the mechanical properties of the PCD material.

Accordingly, it is desirable to remove a metal-solvent catalyst from a PCD material in situations where the PCD material may be exposed to high temperatures. Chemical leaching is often used to dissolve and remove various materials from the PCD layer. For example, chemical leaching may be used to remove metal-solvent catalysts, such as cobalt, from regions of a PCD layer that may experience elevated temperatures during drilling, such as regions adjacent to the working surfaces of the PCD layer.

While chemical leaching is effective at removing metal-solvent catalysts from interstitial regions of a PCD layer, the process of chemical leaching is often lengthy, requiring days or weeks to complete in order to achieve a desired leach depth. Additionally, conventional chemical leaching techniques often involve the use of highly concentrated, toxic, and/or corrosive solutions, such as aqua regia and mixtures including hydrofluoric acid (HF), to dissolve and remove metal-solvent catalysts from polycrystalline diamond materials. The use of highly toxic and corrosive leaching agents can present a danger to individuals and may cause significant damage to the substrate over time.

SUMMARY

The instant disclosure is directed to methods, assemblies, and apparatuses for processing polycrystalline diamond materials. In various embodiments, a method of processing a polycrystalline diamond material may comprise exposing at least a portion of a polycrystalline diamond material to a volume of processing agent for processing at least a portion of a catalyst material from interstitial spaces within the polycrystalline diamond material. The processing agent may comprise, for example, a leaching agent for leaching a catalyst material from interstitial spaces within at least the portion of the polycrystalline diamond material. In additional embodiments, the processing agent may comprise a cleaning agent for cleaning the portion of the polycrystalline diamond material. The method may further comprise applying an elevated body force to the volume of processing agent while at least the portion of the polycrystalline diamond material is exposed to the volume of processing agent, and applying a selected temperature to at least one of the volume of processing agent and at least the portion of the polycrystalline diamond material exposed to the volume of processing agent during application of the elevated body force to the volume of processing agent.

In at least one embodiment, the body force may comprise at least one of a gravitational body force and a centrifugal body force. The processing agent may comprise a liquid solution and the elevated body force may comprise a body force sufficient to prevent a phase change of the liquid solution at a selected temperature. The temperature may comprise a temperature greater than or less than a temperature required for a phase change of the liquid solution under atmospheric conditions. In various embodiments, applying the elevated body force may comprise rotating the volume of processing agent and the polycrystalline diamond material about a rotational axis.

In some embodiments, applying the elevated body force may comprise disposing another volume of fluid adjacent to the volume of processing agent. In one example, the other volume of fluid may have a density greater than the density of the processing agent. Additionally, the other volume of fluid may have a height substantially greater than the height of the volume of processing agent. The other volume of fluid may contact the volume of processing agent. The other volume of fluid may also be open to atmospheric surroundings.

In various embodiments, the method may further comprise disposing a barrier around a portion of the polycrystalline diamond material. Also, in various embodiments, the polycrystalline diamond material may comprise a polycrystalline diamond body bonded to a substrate.

In some embodiments, an assembly for processing a polycrystalline diamond body may comprise a processing container and at least one polycrystalline diamond body disposed in the processing container, the at least one polycrystalline diamond body comprising a catalyst material disposed in interstitial spaces within a polycrystalline diamond material. The assembly may also comprise a volume of processing agent disposed in the processing container, at least a portion of the polycrystalline diamond body being exposed to the volume of processing agent. The processing agent may leach at least a portion of the catalyst material from the polycrystalline diamond body. The assembly may further include a body force application portion for applying an elevated body force to the volume of processing agent while at least the portion of the polycrystalline diamond body is exposed to the volume of processing agent, and a heat application element for increasing the temperature to at least one of the volume of processing agent and at least the portion of the polycrystalline diamond body exposed to the volume of processing agent during application of the elevated body force to the volume of processing agent.

In various embodiments, the processing agent may comprise a liquid solution and the elevated body force may be sufficient to prevent a phase change of the liquid solution at the selected temperature. In some embodiments, the body force application portion may comprise a centrifugal device for rotating the processing container about a rotational axis.

In another embodiment, the body force application portion may comprise a fluid conduit containing another volume of fluid disposed gravitationally above the volume of processing agent. The fluid conduit may comprise, for example, a vertical column. The other volume of fluid may have a density greater than the density of the processing agent. Additionally, the other volume of fluid may have a height substantially greater than the height of the volume of the processing agent. In at least one embodiment, an end of the fluid conduit disposed apart from the processing container may comprise an opening such that the other volume of fluid is open to atmospheric surroundings. In at least one embodiment, a protective barrier may be disposed around a portion of the polycrystalline diamond body.

Features from any of the above-mentioned embodiments may be used in combination with one another in accordance with the general principles described herein. These and other embodiments, features, and advantages will be more fully understood upon reading the following detailed description in conjunction with the accompanying drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate a number of exemplary embodiments and are a part of the specification. Together with the following description, these drawings demonstrate and explain various principles of the instant disclosure.

FIG. 1 is a perspective view of an exemplary superabrasive element according to at least one embodiment.

FIG. 2 is a perspective view of an exemplary superabrasive disc according to at least one embodiment.

FIG. 3A is a cross-sectional side view of a portion of a superabrasive table according to at least one embodiment.

FIG. 3B is a cross-sectional side view of the superabrasive disc according to at least one embodiment.

FIG. 4 is a magnified cross-sectional side view of a portion of the superabrasive table according to at least one embodiment.

FIG. 5 is a cross-sectional side view of an exemplary superabrasive element that is at least partially surrounded by a protective layer according to at least one embodiment.

FIG. 6A is a cross-sectional side view of an exemplary superabrasive material processing assembly according to at least one embodiment.

FIG. 6B is a cross-sectional side view of another exemplary superabrasive material processing assembly according to at least one embodiment.

FIG. 6C is a cross-sectional side view of another exemplary superabrasive material processing assembly according to at least one embodiment.

FIG. 7A is a cross-sectional side view of an exemplary superabrasive material processing assembly according to at least one embodiment.

FIG. 7B is a cross-sectional side view of another exemplary superabrasive material processing assembly according to at least one embodiment.

FIG. 8 is a cross-sectional side view of another exemplary superabrasive material processing assembly according to at least one embodiment.

FIG. 9 is a cross-sectional side view of another exemplary superabrasive material processing assembly according to at least one embodiment.

FIG. 10 is a cross-sectional side view of another exemplary superabrasive material processing assembly according to at least one embodiment.

FIG. 11 is a perspective view of an exemplary drill bit according to at least one embodiment.

FIG. 12 is a partial cut-away perspective view of an exemplary thrust bearing apparatus according to at least one embodiment.

FIG. 13 is a partial cut-away perspective view of an exemplary radial bearing apparatus according to at least one embodiment.

FIG. 14 is a partial cut-away perspective view of an exemplary subterranean drilling system according to at least one embodiment.

FIG. 15 is a flow diagram of an exemplary method of processing a polycrystalline superabrasive material according to at least one embodiment.

Throughout the drawings, identical reference characters and descriptions indicate similar, but not necessarily identical, elements. While the exemplary embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, the instant disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The instant disclosure is directed to leaching systems, methods and assemblies for processing superabrasive elements, such as superabrasive cutting elements, superabrasive bearings, and superabrasive discs. Such superabrasive elements may be used as cutting elements for use in a variety of applications, such as drilling tools, machining equipment, cutting tools, and other apparatuses, without limitation. Superabrasive elements, as disclosed herein, may also be used as bearing elements in a variety of bearing applications, such as thrust bearings, radial bearings, and other bearing apparatuses, without limitation.

As used herein, the terms “superabrasive” and “superhard” may refer to materials exhibiting a hardness that is at least equal to a hardness of tungsten carbide. For example, a superabrasive article may represent an article of manufacture, at least a portion of which may exhibit a hardness that is equal to or greater than the hardness of tungsten carbide. Additionally, the term “solvent,” as used herein, may refer to a single solvent compound, a mixture of two or more solvent compounds, (e.g., an alloy), and/or a mixture of one or more solvent compounds and one or more dissolved compounds. A solvent catalyst may be cobalt, nickel, iron, any Group VIII element, or any alloy or combination thereof. Moreover, the word “cutting” may refer broadly to machining processes, drilling processes, boring processes, or any other material removal process utilizing a cutting element.

FIG. 1 is a perspective view of anexemplary superabrasive element10 according to at least one embodiment. As illustrated inFIG. 1,superabrasive element10 may comprise a superabrasive layer or table14 affixed to or formed upon asubstrate12. Superabrasive table14 may be affixed tosubstrate12 atinterface26, which may be a planar or nonplanar interface.Superabrasive element10 may comprise arear surface18, asuperabrasive face20, and aperipheral surface15. In some embodiments,peripheral surface15 may include asubstrate side surface16 formed bysubstrate12 and asuperabrasive side surface22 formed by superabrasive table14.Rear surface18 may be formed bysubstrate12.

Superabrasive element10 may also comprise a chamfer24 (i.e., sloped or angled) formed by superabrasive table14.Chamfer24 may comprise an angular and/or rounded edge formed at the intersection ofsuperabrasive side surface22 and superabrasive face20. Any other suitable surface shape may also be formed at the intersection ofsuperabrasive side surface22 and superabrasive face20, including, without limitation, an arcuate surface (e.g., a radius, an ovoid shape, or any other rounded shape), a sharp edge, multiple chamfers/radii, a honed edge, and/or combinations of the foregoing. At least one edge may be formed at the intersection ofchamfer24 and superabrasive face20 and/or at the intersection ofchamfer24 and superabrasiveside surface22. For example, cuttingelement10 may comprise one or more cutting edges, such as anedge25 and/or or anedge27.Edge25 and/or or anedge27 may be formed adjacent to chamfer24 and may be configured to be exposed to and/or in contact with a mining formation during drilling.

In some embodiments,superabrasive element10 may be utilized as a cutting element for a drill bit, in which chamfer24 acts as a cutting edge. The phrase “cutting edge” may refer, without limitation, to a portion of a cutting element that is configured to be exposed to and/or in contact with a subterranean formation during drilling. In at least one embodiment,superabrasive element10 may be utilized as a bearing element (e.g., withsuperabrasive face20 acting as a bearing surface) configured to contact oppositely facing bearing elements.

According to various embodiments,superabrasive element10 may also comprise a substrate chamfer formed bysubstrate12. For example, a chamfer comprising an angular and/or rounded edge may be formed bysubstrate12 at the intersection ofsubstrate side surface16 andrear surface18. Any other suitable surface shape may also be formed at the intersection ofsubstrate side surface16 andrear surface18, including, without limitation, an arcuate surface (e.g., a radius, an ovoid shape, or any other rounded shape), a sharp edge, multiple chamfers/radii, a honed edge, and/or combinations of the foregoing.

Substrate12 may comprise any suitable material on which superabrasive table14 may be formed. In at least one embodiment,substrate12 may comprise a cemented carbide material, such as a cobalt-cemented tungsten carbide material and/or any other suitable material. In some embodiments,substrate12 may include a suitable metal-solvent catalyst material, such as, for example, cobalt, nickel, iron, and/or alloys thereof.Substrate12 may also include any suitable material including, without limitation, cemented carbides such as titanium carbide, niobium carbide, tantalum carbide, vanadium carbide, chromium carbide, and/or combinations of any of the preceding carbides cemented with iron, nickel, cobalt, and/or alloys thereof. Superabrasive table14 may be formed of any suitable superabrasive and/or superhard material or combination of materials, including, for example PCD. According to additional embodiments, superabrasive table14 may comprise cubic boron nitride, silicon carbide, polycrystalline diamond, and/or mixtures or composites including one or more of the foregoing materials, without limitation.

FIG. 2 is a perspective view of anexemplary superabrasive disc28 according to at least one embodiment.Superabrasive disc28 may be formed using any suitable technique. According to some embodiments,superabrasive disc28 may comprise a PCD superabrasive table14 fabricated by subjecting a plurality of diamond particles to an HPHT sintering process in the presence of a metal-solvent catalyst (e.g., cobalt, nickel, iron, or alloys thereof) to facilitate intergrowth between the diamond particles and form a PCD body comprised of bonded diamond grains that exhibit diamond-to-diamond bonding therebetween. For example, the metal-solvent catalyst may be mixed with the diamond particles, infiltrated from a metal-solvent catalyst foil or powder adjacent to the diamond particles, infiltrated from a metal-solvent catalyst present in a cemented carbide substrate, or combinations of the foregoing. The bonded diamond grains (e.g., sp³-bonded diamond grains), so-formed by HPHT sintering the diamond particles, define interstitial regions with the metal-solvent catalyst disposed within the interstitial regions of the as-sintered PCD body. The diamond particles may exhibit a selected diamond particle size distribution. Polycrystalline diamond elements, such as those disclosed in U.S. Pat. Nos. 7,866,418 and 8,297,382, the disclosure of each of which is incorporated herein, in its entirety, by this reference, may have magnetic properties in at least some regions as disclosed therein and leached regions in other regions as disclosed herein.

In some examples,superabrasive disc28 may be created by first forming asuperabrasive element10 that includes asubstrate12 and a superabrasive table14, as detailed above in reference toFIG. 1. Oncesuperabrasive element10 has been produced, superabrasive table14 may be separated fromsubstrate12 to formsuperabrasive disc28. For example, prior to or following leaching, superabrasive table14 may be separated and/or finished fromsubstrate12 using any number of suitable processes, including a lapping process, a grinding process, electrical-discharge machining (e.g., wire EDM) process, and/or any other suitable material-removal process, without limitation.

The plurality of diamond particles used to form superabrasive table14 comprising the PCD material may exhibit one or more selected sizes. The one or more selected sizes may be determined, for example, by passing the diamond particles through one or more sizing sieves or by any other method. In an embodiment, the plurality of diamond particles may include a relatively larger size and at least one relatively smaller size. As used herein, the phrases “relatively larger” and “relatively smaller” refer to particle sizes determined by any suitable method, which differ by at least a factor of two (e.g., 40 μm and 20 μm). More particularly, in various embodiments, the plurality of diamond particles may include a portion exhibiting a relatively larger size (e.g., 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 15 μm, 12 μm, 10 μm, 8 μm) and another portion exhibiting at least one relatively smaller size (e.g., 30 μm, 20 μm, 15 μm, 12 μm, 10 μm, 8 μm, 4 μm, 2 μm, 1 μm, 0.5 μm, less than 0.5 μm, 0.1 μm, less than 0.1 μm). In another embodiment, the plurality of diamond particles may include a portion exhibiting a relatively larger size between about 40 μm and about 15 μm and another portion exhibiting a relatively smaller size between about 12 μm and 2 μm. Of course, the plurality of diamond particles may also include three or more different sizes (e.g., one relatively larger size and two or more relatively smaller sizes), without limitation. Different sizes of diamond particle may be disposed in different locations within a polycrystalline diamond volume, without limitation. According to at least one embodiment, disposing different sizes of diamond particles in different locations may facilitate control of a leach depth, as will be described in greater detail below.

FIG. 3A is a cross-sectional side view of a portion of an exemplary superabrasive table14, such as the superabrasive tables14 illustrated inFIGS. 1 and 2. Superabrasive table14 may comprise a composite material, such as a PCD material. A PCD material may include a matrix of bonded diamond grains and interstitial regions defined between the bonded diamond grains. Such interstitial regions may be at least partially filled with various materials. In some embodiments, a metal-solvent catalyst may be disposed in at least some or a portion of the interstitial regions in superabrasive table14. Tungsten and/or tungsten carbide may also be present in at least some or a portion of the interstitial regions.

According to various embodiments, materials may be deposited in or infiltrated into interstitial regions during processing of superabrasive table14. For example, material components ofsubstrate12 may migrate into a mass of diamond particles used to form a superabrasive table14 during HPHT sintering. As the mass of diamond particles is sintered, a metal-solvent catalyst may melt and flow fromsubstrate12 into the mass of diamond particles. As the metal-solvent flows into superabrasive table14, it may dissolve and/or carry additional materials, such as tungsten and/or tungsten carbide, fromsubstrate12 into the mass of diamond particles. As the metal-solvent catalyst flows into the mass of diamond particles, the metal-solvent catalyst, and any dissolved and/or undissolved materials, may at least partially fill spaces between the diamond particles. The metal-solvent catalyst may facilitate bonding of adjacent diamond particles to form a PCD layer.

Following sintering, any materials, such as, for example, the metal-solvent catalyst, tungsten, and/or tungsten carbide, may remain in interstitial regions within superabrasive table14. Such materials in the interstitial regions may reduce the thermal stability of superabrasive table14 at elevated temperatures. In some examples, differences in thermal expansion coefficients between diamond grains in the as-sintered PCD body and a metal-solvent catalyst in interstitial regions between the diamond grains may weaken portions of superabrasive table14 that are exposed to elevated temperatures, such as temperatures developed during drilling and/or cutting operations. The weakened portions of superabrasive table14 may be excessively worn and/or damaged during the drilling and/or cutting operations.

To improve the performance, heat resistance, and/or the thermal stability of a surface of superabrasive table14, particularly in situations where the PCD material may be exposed to elevated temperatures, at least a portion of a metal-solvent catalyst, such as cobalt, may be removed from at least a portion of superabrasive table14. Additionally, tungsten and/or tungsten carbide may be removed from at least a portion of superabrasive table14. Removing a metal-solvent catalyst from the as-sintered PCD body may reduce damage to the PCD material of superabrasive table14 caused by expansion of the metal-solvent catalyst. At least a portion of a metal-solvent catalyst, such as cobalt, as well as other materials, may be removed from at least a portion of the as-sintered PCD body using any suitable technique, without limitation.

For example, chemical leaching may be used to remove a metal-solvent catalyst from the as-sintered PCD body up to a depth D from a surface of superabrasive table14, as illustrated inFIG. 3A. As shown inFIG. 3A, depth D may be measured relative to an external surface of superabrasive table14, such assuperabrasive face20, superabrasiveside surface22, and/orchamfer24. In some examples, a metal-solvent catalyst may be removed from superabrasive table14 up to a depth D from the top of the PCD to through the whole disc or to the interface. In additional examples, a metal-solvent catalyst may be removed from superabrasive table14 up to a depth D of between approximately 100 and 2500 μm. The as-sintered PCD body may be leached by immersion in an acid or acid solution, such as aqua regia, nitric acid, hydrofluoric acid, or subjected to another suitable process to remove at least a portion of the metal-solvent catalyst from the interstitial regions of the PCD body and form superabrasive table14 comprising a PCD table. For example, the as-sintered PCD body may be immersed in an acid solution for about 2 to about 7 days (e.g., about 3, 5, or 7 days) or for a few weeks (e.g., about 4 weeks), depending on the process employed.

In some embodiments, only selected portions of the as-sintered PCD body may be leached, leaving remaining portions of resulting superabrasive table14 unleached. For example, some portions of one or more surfaces of the as-sintered PCD body may be masked or otherwise protected from exposure to a leaching agent and/or gas mixture while other portions of one or more surfaces of the as-sintered PCD body may be exposed to the leaching agent and/or gas mixture. For an example, U.S. Pat. Nos. 4,224,380 and 7,972,395, the disclosure of each of which is incorporated herein, in its entirety, by this reference, disclose leaching solutions that may be used for processing superabrasive elements as disclosed herein. Other suitable techniques may be used for removing a metal-solvent catalyst and/or other materials from the as-sintered PCD body or may be used to accelerate a chemical leaching process. For example, exposing the as-sintered PCD body to heat, pressure, electric field/current, microwave radiation, and/or ultrasound may be employed to leach or to accelerate a chemical leaching process, without limitation. Following leaching, superabrasive table14 may comprise a volume of PCD material that is at least partially free or substantially free of a metal-solvent catalyst.

Following leaching, superabrasive table14 may comprise afirst volume30 that is substantially free of a metal-solvent catalyst. However, small amounts of catalyst may remain within interstices that are inaccessible to the leaching process.First volume30 may extend from one or more surfaces of superabrasive table14 (e.g.,superabrasive face20, superabrasiveside surface22, and/or chamfer24) to a depth D from the one or more surfaces.First volume30 may be located adjacent one or more surfaces of superabrasive table14.

Following leaching, superabrasive table may also comprise asecond volume31 that contains a metal-solvent catalyst. An amount of metal-solvent catalyst insecond volume31 may be substantially the same prior to and following leaching. In various embodiments,second volume31 may be remote from one or more exposed surfaces of superabrasive table14. In various embodiments, an amount of metal-solvent catalyst infirst volume30 and/orsecond volume31 may vary at different depths in superabrasive table14.

In at least one embodiment, superabrasive table14 may include atransition region29 betweenfirst volume30 andsecond volume31.Transition region29 may include amounts of metal-solvent catalyst varying between an amount of metal-solvent catalyst infirst volume30 and an amount of metal-solvent catalyst insecond volume31. In various examples,transition region29 may comprise a relatively narrow region betweenfirst volume30 andsecond volume31.

FIG. 3B is a cross-sectional side view of asuperabrasive disc28, such as thesuperabrasive disc28 illustrated inFIG. 2. As shown inFIG. 3B,superabrasive disc28 may comprise a superabrasive table14 having asuperabrasive face20, asuperabrasive side surface22, arear superabrasive face23, andchamfer24. As described above in reference toFIG. 3A, a metal-solvent catalyst, as well as other materials, may be removed from at least a portion ofsuperabrasive disc28. Accordingly,superabrasive disc28 may comprise afirst volume30 that is substantially free of a metal-solvent catalyst and asecond volume31 that contains a metal-solvent catalyst. As described above, small amounts of catalyst may remain within interstices that are inaccessible to the leaching process infirst volume30.

In at least one example, as shown inFIG. 3B,first volume30 may extend around a substantial exterior portion ofsuperabrasive disc28. For example,superabrasive disc28 may be submerged in or exposed to a leaching agent so thatsuperabrasive face20, superabrasiveside surface22,rear superabrasive face23, and chamfers24 are exposed to the leaching agent, resulting in afirst volume30 that extends substantially aroundsuperabrasive disc28. In some examples, only a portion ofsuperabrasive disc28 may be exposed to a leaching agent, resulting in afirst volume30 that extends around only a portion ofsuperabrasive disc28.

FIG. 4 is a magnified cross-sectional side view of a portion of the superabrasive table14 illustrated inFIG. 3A. As shown inFIG. 4, superabrasive table14 may comprisegrains32 andinterstitial regions34 betweengrains32 defined by grain surfaces36.Grains32 may comprise grains formed of any suitable superabrasive material, including, for example, diamond grains. At least some ofgrains32 may be bonded to one or moreadjacent grains32, forming a polycrystalline diamond matrix.

Interstitial material38 may be disposed in at least some ofinterstitial regions34.Interstitial material38 may comprise, for example, a metal-solvent catalyst, tungsten, and/or tungsten carbide. As shown inFIG. 4,interstitial material38 may not be present in at least some ofinterstitial regions34. At least a portion ofinterstitial material38 may be removed from at least some ofinterstitial regions34 during a leaching procedure. For example, a substantial portion ofinterstitial material38 may be removed fromfirst volume30 during a leaching procedure. Additionally,interstitial material38 may remain in asecond volume31 following a leaching procedure.

In some examples,interstitial material38 may be removed from table14 to a depth that improves the performance and heat resistance of a surface of superabrasive table14 to a desired degree. In some embodiments,interstitial material38 may be removed from superabrasive table14 to a practical limit. In order to removeinterstitial material38 from superabrasive table14 to a depth beyond the practical limit, for example, significantly more time, temperature, and/or body force may be required. In some embodiments,interstitial material38 may be removed from superabrasive table14 to a practical limit where interstitial material remains in at least a portion of superabrasive table14. In various embodiments, superabrasive table14 may be fully leached so thatinterstitial material38 is substantially removed from a substantial portion of superabrasive table14. In at least one embodiment,interstitial material38 may be leached from a superabrasive material, such as a PCD material in superabrasive table14, by exposing the superabrasive material to a suitable leaching agent.Interstitial material38 may include a metal-solvent catalyst, such as cobalt. Relatively less concentrated and corrosive solutions may be inhibited from leaching a PCD article at a sufficient rate.

In various examples, as will be discussed in greater detail below, at least a portion of a superabrasive material and/or the leaching agent may be heated (e.g., a temperature greater than approximately 50° C.) during leaching. According to additional embodiments, at least a portion of a superabrasive material and a leaching agent may be exposed to at least one of an electric current, microwave radiation, and/or ultrasonic energy. By exposing at least a portion of a superabrasive material to an electric current, microwave radiation, and/or high frequency ultrasonic energy as the superabrasive material is exposed to a leaching agent, the rate at which the superabrasive material is leached and/or the depth to which the superabrasive material is leached may be increased.

FIG. 5 is a cross-sectional side view of anexemplary superabrasive element10 that is at least partially surrounded by aprotective layer40 according to at least one embodiment. As shown inFIG. 5, at least a portion ofsuperabrasive element10, includingsubstrate12, may be surrounded byprotective layer40. According to various embodiments,protective layer40 may comprise an inert cup, a protective coating, and/or any other suitable protective layer that inhibits or prevents a leaching agent, a cleaning agent, and/or any other desired processing agent from contacting at least a portion of thesuperabrasive element10.Protective layer40 may prevent or inhibit a leaching agent from chemically damaging certain portions ofsuperabrasive element10, such as, for example,substrate12, a portion of superabrasive table14, or both, during leaching.Protective layer40 may be selectively formed oversubstrate12 and/or a selected portion of superabrasive table14 in any pattern, design, or as otherwise desired, without limitation. Such a configuration may provide selective leaching of superabrasive table14, which may be beneficial. Following leaching of superabrasive table14,protective layer40 may be removed fromsuperabrasive element10.

FIG. 6A is a cross-sectional side view of an exemplary superabrasivematerial processing assembly50 for processing asuperabrasive element10 according to at least one embodiment. The processing ofsuperabrasive element10 may include, for example, leaching, cleaning, and/or rinsingsuperabrasive element10, without limitation. A cleaning agent may include any material suitable for cleaning the leaching agent and other compounds, such as dissolved compounds including a catalyst material, from interstitial spaces insuperabrasive element10 after completion of the leaching process.Superabrasive element10 may be exposed to the cleaning agent in any suitable manner, such as, for example, by submerging at least a portion of the polycrystalline diamond material in the cleaning agent. As shown inFIG. 6A, asuperabrasive element10 may be positioned within aprocessing container52. Processingassembly50 and/or any of the other processing assembly embodiments illustrated herein may additionally or alternatively be used to leach, clean, or otherwise process any other type of superabrasive body, including, for example, PDC, a PDC insert, a superabrasive element, or a disc (e.g.,superabrasive disc28 illustrated inFIG. 2) that is not coupled to a substrate.

As illustrated inFIG. 6A, processingcontainer52 may have arear wall56 and aside wall54 defining acavity58.Rear wall56 andside wall54 may have any suitable shape, without limitation.Cavity58 may contain aprocessing agent60 that at least partially surroundssuperabrasive element10 such that at least a portion ofsuperabrasive element10 is exposed toprocessing agent60. Afirst volume61 ofprocessing agent60 may be disposedadjacent superabrasive element10.First volume61 represents a volume of fluid that is positioned adjacent to superabrasiveelement10 and upon which a body force is exerted (e.g., due to its own mass, the mass of another fluid, and/or by any other mechanism described herein for generating and/or exerting a body force, without limitation).Superabrasive element10 may be positioned infirst volume61 so thatsuperabrasive element10 contactsrear wall56 ofprocessing container52. In some embodiments,superabrasive element10 may be positioned and/or secured withinprocessing container52 using any suitable mechanism, without limitation.Processing agent60 may be a leaching agent, a cleaning agent, a rinsing agent, and/or any other suitable agent for processingsuperabrasive element10.

As shown inFIG. 6A, a protective layer may at least partially surroundsuperabrasive element10 to preventprocessing agent60 from contacting at least a portion ofsuperabrasive element10. For example,protective layer40 may surround asubstrate12, while at least portions of superabrasive table14, includingsuperabrasive face20,chamfer24, and/orsuperabrasive side surface22 remain exposed toprocessing agent60. In this way, portions ofsuperabrasive element10, such assubstrate12, can be selectively inhibited or prevented from contactingprocessing agent60 during processing. In an additional embodiment,superabrasive element10 or any other suitable superabrasive body (e.g.,superabrasive disc28 shown inFIG. 2) may be leached with or without a protective layer disposed thereon.

In some embodiments, a body force on processingagent60 andsuperabrasive element10 may be developed through other mechanisms. For example, processingcontainer52 may be spun in a centrifuge in order to develop a body force in processingagent60 and/orsuperabrasive element10, (as will also be described in more detail below with reference toFIGS. 7A and 7B). In additional embodiments, a second fluid having a different density than processingagent60 may be placed adjacent to processingagent60 in order exert a body force on processing agent60 (as will be discussed in greater detail below with reference toFIGS. 9 and 10).

According to various embodiments, at least a portion ofprocessing agent60 and/orsuperabrasive element10 may be heated during processing. For example, as illustrated inFIG. 6A, aheating element64 may be disposed around at least a portion ofprocessing container52. For example,heating element64 may at least partially surround a portion ofprocessing container52 adjacentfirst volume61 ofprocessing agent60 and/orsuperabrasive element10 in order to generate and/or apply heat to processingagent60 and/orsuperabrasive element10. Heating ofprocessing agent60 and/orsuperabrasive element10 may additionally or alternatively be accomplished by any other suitable means, such as, for example, resistance-based heating, inductive heating, convection heating, dielectric heating, and/or combustion source heating, without limitation. Additionally, heating elements may be placed in different positions, such as, for example, within processingcontainer52, withinside wall54 and/or withinrear wall56 ofprocessing container52. Additionally or alternatively,processing agent60 and/orsuperabrasive element10 may be heated directly by applying an electric current and/or field or microwaves thereto, or apre-heated processing agent60 may be injected intofirst volume61 ofprocessing container52.

According to various embodiments, a superabrasive material may be exposed to aprocessing agent60, such as a leaching agent, in order to remove various materials from the interstitial regions in the superabrasive material. Certain techniques may be utilized to accelerate leaching ofsuperabrasive element10. For example, adding heat to increase the temperature ofprocessing agent60 and/orsuperabrasive element10 may increase the leaching efficiency and/or decrease an amount of time required to complete the leaching process. Based, for example, on the type ofprocessing agent60 used, the temperature ofprocessing agent60 and/orsuperabrasive element10, and how long the process is carried out, the amount of interstitial materials removed from superabrasive table14, the depth D to which the materials are removed from superabrasive table14, and/or the amount of materials remaining in the interstitial regions of superabrasive table14 may be controlled.

In various examples, at least a portion ofsuperabrasive element10 andprocessing agent60 are exposed to a temperature that is close to, at, below, or above a temperature required for a phase change to the gas phase under standard conditions (e.g., standard temperature and pressure). According to some embodiments, depending on the type ofprocessing agent60 used,processing agent60 and/orsuperabrasive element10 may be heated to temperatures greater than approximately 50° C. For example,processing agent60 and/orsuperabrasive element10 may be heated to temperatures ranging from approximately 50° C. up to, or in excess of 500° C. (e.g., approximately 60° C., 70° C., 80° C., 90° C., 100° C., 120° C., 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., 210° C., 220° C., 230° C., 240° C., 250° C., 260° C., 270° C., 280° C., 290° C., 300° C., 310° C., 320° C., 330° C., 340° C., 350° C., 360° C., 370° C., 380° C., 390° C., 400° C., 410° C., 420° C., 430° C., 440° C., 450° C., 460° C., 470° C., 480° C., 490° C., 500° C.).

Although increasing the temperature ofprocessing agent60 may, in some configurations, lead to accelerated leaching, leaching may be improved if processingagent60 is kept from changing to a gas phase. For example, reducing or preventing phase change, and/or excessive evaporation of processingagent60 may prevent loss of processingagent60 and/or one or more components ofprocessing agent60 from processingcontainer52. Preventing phase change, and/or excessive evaporation of processingagent60 may also ensure consistent submersion and orientation ofsuperabrasive element10 inprocessing agent60. In order to prevent or reduce phase change of theprocessing agent60, a sufficient body force may be exerted onfirst volume61 ofprocessing agent60.

Optionally, as illustrated inFIG. 6B, processingassembly50 may additionally include asecond volume62 comprisingprocessing agent60 and/or another fluid composition disposed withinprocessing container52. For example,second volume62 ofprocessing agent60 may be disposed adjacent tofirst volume61.Boundary line47 illustrated inFIG. 6A represents a boundary betweenfirst volume61 andsecond volume62. While in some embodiments, fluid compositions inprocessing container52 may flow freely betweenfirst volume61 andsecond volume62,first volume61 represents a volume of fluid that is positioned adjacent to superabrasiveelement10 and upon which a body force is exerted (e.g., due to its own mass, bysecond volume62, and/or by any other mechanism described herein for generating and/or exerting a body force, without limitation).

Second volume62 ofprocessing agent60 may exert a body force onfirst volume61 ofprocessing agent60, thereby facilitating processing ofsuperabrasive element10, as will be described in further detail below. In some embodiments, a body force on processingagent60 andsuperabrasive element10 may be developed through other mechanisms. For example, processingcontainer52 may be spun in a centrifuge in order to develop a body force in processingagent60 and/orsuperabrasive element10, (as will also be described in more detail below with reference toFIGS. 7A and 7B). In additional embodiments, a second fluid having a different density than processingagent60 may be placed adjacent to processingagent60 in order exert a body force on processing agent60 (as will be discussed in greater detail below with reference toFIGS. 9 and 10).

According to some embodiments, as illustrated inFIG. 6C, processingassembly50 may additionally include a resilient seal41 (e.g., a V-seal or an O-ring) surrounding at least a portion ofsuperabrasive element10.Resilient seal41 may be made of any suitable material for protecting at least a portion ofsuperabrasive element10 from processingagent60, without limitation. For example,resilient seal41 may comprise an elastic polymeric material.Superabrasive element10 andresilient seal41 may be placed incavity58 ofprocessing container52 so thatresilient seal41contacts side wall54 ofprocessing container52 and surrounds at least a portion ofside surface22 of superabrasive table14 and/orside surface16 ofsubstrate12. According to at least one embodiment,resilient seal41 may be placed aroundsuperabrasive element10 prior to placingsuperabrasive element10 intocavity58 ofprocessing container52.

Withresilient seal41 disposed betweenside wall54 ofprocessing container52 and side surfaces22 and/or16 ofsuperabrasive element10, a sealedcavity49 may be defined byresilient seal41,side surface16 ofsubstrate12,side wall54 ofprocessing container52, andrear wall56 ofprocessing container52.Processing agent60 may be disposed in processingcontainer52 adjacent to superabrasiveelement10 andresilient seal41 such thatprocessing agent60 is prevented or inhibited from entering sealedcavity49.Resilient seal41 may isolatesubstrate12 and/or at least a portion of superabrasive table14 from processingagent60 so as to prevent and/or inhibitsubstrate12 and/or at least a portion of superabrasive table14 from contactingprocessing agent60.Resilient seal41 may prevent or inhibitprocessing agent60 from chemically damaging certain portions ofsuperabrasive element10, such as, for example,substrate12, a portion of superabrasive table14, or both, during leaching. Such a configuration may further provide selective leaching of superabrasive table14.

As illustrated inFIG. 6C,resilient seal41 may have a substantially V-shaped cross section. This cross section may allowresilient seal41 to be compressed by processingagent60. For example,resilient seal41 may be compressed by the weight and/or centrifugal force of aprocessing agent60 causing a body force to be applied toresilient seal41 indirection43.Resilient seal41 may further be compressed due to an increased body force acting on processingagent60 due rotation in a centrifuge, as described with respect toFIGS. 7A and 7B below, or due to a second fluid exerting an added force on processingagent60 as described with respect toFIGS. 9-10 below. Compression ofresilient seal41 due to a body force applied by processingagent60 may causeresilient seal41 to expand betweenside surface16 andside wall54. Such expansion may causeresilient seal41 to exert an inward force against side surfaces22 and/or16 ofsuperabrasive element10, thus tightening the seal aroundsuperabrasive element10 and preventing or inhibitingprocessing agent60 from contactingsubstrate12. While a v-shaped cross section is shown,resilient seal41 may optionally have a circular cross-section, a rectangular cross-section, or any other suitable cross-sectional shape for creating a seal betweensuperabrasive element10 andside wall54 ofprocessing container52.

FIG. 7A is a cross-sectional side view of an exemplary superabrasivematerial processing assembly150 according to at least one embodiment. A processing assembly for processing asuperabrasive element10 may use high-speed rotation ofprocessing chamber152 to develop a centrifugal body force in processingagent60. For example, as shown inFIG. 7A, processingassembly150 may include acentrifuge166 that rotates processingcontainers152 at high speed aboutrotational axis168 in rotational direction Di. One ormore processing containers152 may be coupled tocentrifuge166. For example, two processingcontainers152 may be coupled tocentrifuge166 as shown inFIG. 7A.

As illustrated inFIG. 7A, eachprocessing chamber152 may have arear wall156 and aside wall154 defining acavity158 withinprocessing chamber152.Cavity158 of eachprocessing chamber152 may be open to atmospheric surroundings through anopening159 defined in a portion ofprocessing chamber152 that is disposed apart fromsuperabrasive element10 and/orfirst volume161.Cavity158 may contain aprocessing agent60 that at least partially surroundssuperabrasive element10 such that at least a portion ofsuperabrasive element10 is exposed toprocessing agent60. Afirst volume161 ofprocessing agent60 may be disposedadjacent superabrasive element10. Additionally, optionally, asecond volume162 ofprocessing agent60 may be disposed withinprocessing chamber152 adjacent tofirst volume161 atboundary line147.Superabrasive element10 may be positioned infirst volume161 so thatsuperabrasive element10 contactsrear wall156 ofprocessing chamber152. In some embodiments,superabrasive element10 may be positioned and/or secured withinprocessing chamber152 using any suitable mechanism, without limitation.Processing agent60 may be a leaching agent, a cleaning agent, a rinsing agent, and/or any other suitable agent for processingsuperabrasive element10.

In one embodiment, at least a portion ofsuperabrasive element10 andprocessing agent60 may be heated to a temperature that is at, close to, below, or above the temperature for phase change ofprocessing agent60 under standard conditions (e.g., standard temperature and pressure). Heating ofprocessing agent60 may be accomplished by any suitable means, such as, for example, resistance-based heating, inductive heating, dielectric heating, and/or combustion source heating, without limitation. Additionally, heating elements may be placed in different positions, such as, for example, withincavity158 ofprocessing chamber152, withinside wall154 and/orrear wall156 ofprocessing chamber152. Additionally or alternatively,processing agent60 and/orsuperabrasive element10 may be heated directly by applying an electric current or field thereto, or to theside wall154 and/orrear wall156 ofprocessing chamber152, or apre-heated processing agent60 may be injected intofirst volume161 ofprocessing chamber152.

As described above, preventing phase change, and/or excessive evaporation of processingagent60 may further facilitate leaching ofsuperabrasive element10 by preventing loss of processingagent60 and/or one or more components ofprocessing agent60 from processingchamber152. A phase change may be prevented or inhibited by developing a sufficient centrifugal body force onfirst volume161 ofprocessing agent60 by spinningprocessing chamber152 withincentrifuge166 during processing ofsuperabrasive element10.

Centrifuge166 may be spun in rotational direction Di at a rotational frequency sufficient to exert a centrifugal body force onfirst volume161 ofprocessing agent60 that is sufficient to prevent or inhibitprocessing agent60 from changing phase and/or excessively evaporating at an elevated temperature. For example, in order to prevent or inhibit a phase change, and/or excessive evaporation of aprocessing agent60 having a density that is approximately the same as water and that is heated to a temperature of approximately 200° C., acentrifuge166 having a rotational radius R₁of 20 cm might be spun at a rotational frequency of approximately 7,000, 8,000, 9,000, or 10,000 RPM or more, thereby subjectingfirst volume161 to an acceleration level of approximately 14,000; 16,000; 17,000; 18,000; 19,000; 20,000 g_nor more where g is 9.81 m/s². According to at least one embodiment, rotational radius R₁is measured fromrotational axis168 to a portion offirst volume161 of processing agent160.

Centrifuge166 may have any suitable rotational radius R₁and may be rotated at any suitable rotational frequency, without limitation. The RPM required to exert a desired centrifugal body force may vary based on the rotational radius R₁ofcentrifuge166 as well as the height and density of processing agent160. For example, acentrifuge166 with a larger radius (e.g., R1) will require a lower rotational frequency (i.e., lower RPM) to produce the required centrifugal body force on theprocessing agent60, while a centrifuge with a smaller radius will require a higher rotational frequency (i.e., higher RPM) to produce the required force. Additionally, the centrifugal body force required to prevent or inhibit a phase change and/or excessive evaporation of processingagent60 may vary depending on the phase change temperature of theparticular processing agent60 used. Eachdifferent processing agent60 may have a different composition and/or phase change temperature when compared to other processing agents and would, therefore, require a different centrifugal body force to prevent or inhibit a phase change of theprocessing agent60 during processing of thesuperabrasive element10.

According to some embodiments, as illustrated inFIG. 7B,processing assembly150 may optionally include apiston element167 disposed withinprocessing chamber152 adjacent tofirst volume161 ofprocessing agent60 atboundary line147. In some embodiments,piston element167 may be at least partially surrounded by a seal element169 (e.g. an O-ring) to sealprocessing agent60 withinfirst volume161.Piston element167 may exert a force on processingagent60 due to high speed rotation ofcentrifuge166.

As described above, preventing or inhibiting phase change and/or excessive evaporation of processingagent60 may further facilitate leaching ofsuperabrasive element10 by preventing or inhibiting loss of processingagent60 and/or one or more components ofprocessing agent60 from processingchamber152. A phase change may be prevented or inhibited by developing a sufficient centrifugal body force onfirst volume161 ofprocessing agent60 by spinningprocessing chamber152 withincentrifuge166 during processing ofsuperabrasive element10. Withpiston element167 exerting an additional force on processingagent60, a lower rotational frequency (i.e., lower RPM) may be required to produce the required centrifugal body force on processingagent60 to prevent or inhibit a phase change and/or excessive evaporation of processingagent60 during processing of thesuperabrasive element10.

WhileFIGS. 7A and 7B illustratesuperabrasive element10 at least partially protected from processingagent60 usingprotective layer40,superabrasive element10 may optionally be at least partially protected from contact withprocessing agent60 using a resilient seal (e.g.,resilient seal41 illustrated inFIG. 6C) and/or any other suitable protection from processingagent60, without limitation.

FIG. 8 is a cross-sectional side view of an exemplary superabrasivematerial processing assembly250 according to at least one embodiment. As shown inFIG. 8,processing assembly250 may include aprocessing container252 comprising any suitable fluid conduit, such as, for example, substantially a vertical column.Side wall254 andrear wall256 ofprocessing container252 may define acavity258 within theprocessing container252. Afirst volume261 ofprocessing agent60 may be disposedadjacent superabrasive element10 and asecond volume262 may be disposed withinprocessing container252 adjacent tofirst volume261 such thatsecond volume262 exerts a gravitational body force onfirst volume261.Second volume262 may be adjacent tofirst volume261 atboundary line247

Each offirst volume261 andsecond volume262 may have heights of height H₁and height H₂, respectively. As shown inFIG. 8, a height H₂ofsecond volume262 may be greater than a height H₁offirst volume261.Cavity258 ofprocessing container252 may be open to atmospheric surroundings through anopening259 defined in a portion of processing container252 (e.g., a vertically upper end) that is disposed apart fromsuperabrasive element10 and/orfirst volume261.Second volume262 may include processingagent60 and/or may include another fluid having a density different than processingagent60. Fluid insecond volume262 may push gravitationally downward (i.e., in the direction G of gravitational acceleration) onfirst volume261 so as to exert a body force on processingagent60 sufficient to prevent or inhibit a phase change ofprocessing agent60 during processing ofsuperabrasive element10.

Processingcontainer252 may have a longitudinal height accommodating a height H₂of fluid that exerts a gravitational body force onfirst volume261 ofprocessing agent60 that is sufficient to prevent or inhibitprocessing agent60 from changing phase, and/or excessively evaporating even if it is heated. Height H₂ofsecond volume262 may be significantly greater than height H₁offirst volume261 so as to exert a sufficient body force onfirst volume261. For example, height H₂may be one or more orders of magnitude greater than height H₁.

FIG. 9 is a cross-sectional side view of an exemplary superabrasivematerial processing assembly350 according to at least one embodiment. As shown inFIG. 9,side wall354 andrear wall356 ofprocessing container352 may define acavity358 within theprocessing container352. Afirst volume361 ofprocessing agent60 may be disposedadjacent superabrasive element10. Optionally, asecond volume362 may be disposed withinprocessing container352 adjacent tofirst volume361 such thatsecond volume362 exerts a body force (e.g., gravitational and/or centrifugal) onfirst volume361.Second volume362 may be adjacent tofirst volume361 atboundary line347. A partial or substantial portion ofsecond volume362 may comprise asecond fluid372 in addition to or excludingprocessing agent60. Fluid insecond volume362 may exert a body force on processingagent60 sufficient to prevent or inhibit a phase change ofprocessing agent60 during processing ofsuperabrasive element10.Superabrasive element10 may be positioned and/or secured withinprocessing container352 using any suitable mechanism, without limitation.Processing agent60 may be a leaching agent, a cleaning agent, a rinsing agent, or any other suitable agent for processing asuperabrasive element10.Cavity358 ofprocessing container352 may be open to atmospheric surroundings through anopening359 at or near the top of theprocessing container352.

At least a portion ofsuperabrasive element10 andprocessing agent60 may exhibit a temperature that is close to, at, below, or above a phase change temperature ofprocessing agent60 under standard conditions (e.g., standard temperature and pressure). Heating ofprocessing agent60 may be accomplished by any suitable means, such as, for example, resistance-based heating, inductive heating, microwave heating, dielectric heating, and/or combustion source heating, without limitation. Additionally, heating elements may be placed in different positions, such as, for example, withincavity358 ofprocessing container352 and/or within the walls ofprocessing container352. Additionally or alternatively,processing agent60 and/orsuperabrasive element10 may be heated by applying an electric current or field thereto, to any of the walls ofprocessing container352, or apre-heated processing agent60 may be injected intofirst volume361 ofprocessing container352.

As described above, preventing or inhibiting phase change and/or excessive evaporation of processingagent60 may further facilitate leaching and/or cleaning ofsuperabrasive element10 by preventing or inhibiting loss of processingagent60 and/or one or more components ofprocessing agent60 from processingcontainer352.Second fluid362 may be disposed gravitationally above processingagent60 so as to exert a sufficient gravitational body force onfirst volume361 ofprocessing agent60 to prevent or inhibit a phase change, and/or excessive evaporation during processing ofsuperabrasive element10.

According to some embodiments,second fluid372 may have a different density (e.g., a lower density) than processingagent60 and may be disposed adjacent to processingagent60 in order to exert a gravitational body force on processingagent60 infirst volume361 so as to prevent or inhibit a phase change ofprocessing agent60 during processing ofsuperabrasive element10.Second fluid372 may comprise any suitable fluid composition, without limitation.Processing agent60 andsecond fluid372 may comprise separate fluid compositions that are substantially insoluble with respect to each other in order to maintain separation betweenprocessing agent60 andsecond fluid372. In at least one embodiment,second fluid372 may act as an evaporation barrier inhibiting or preventing evaporation of processingagent60. In some embodiments,second fluid372 may comprise a fluid having a density less than that ofprocessing agent60.

Second fluid372, which may be disposed gravitationally above processingagent60 insideprocessing container352, may exert a downward gravitational body force on processingagent60 assecond fluid372 pushes gravitationally downward (i.e., in the direction G of gravitational acceleration) againstprocessing agent60 atfluid interface386. The amount of gravitational body force exerted on processingagent60 under standard conditions (e.g., standard temperature and pressure) is related to the density ofsecond fluid372 and the height ofsecond fluid372 relative to processingagent60.Second fluid372 may have a height H4 that is much greater than a height H3 ofprocessing agent60 so as to exert a sufficient gravitational body force on processingagent60 and prevent or inhibit a phase change and/or excessive evaporation of processingagent60 during processing ofsuperabrasive element10.

FIG. 10 is a cross-sectional side view of an exemplary superabrasivematerial processing assembly450 according to at least one embodiment. As shown inFIG. 10,container walls454 anddivider483 ofprocessing container452 may define acavity458 withinprocessing container452.Container walls454 ofprocessing container452 may define anelongated portion482, atransition portion480, and aprocessing portion484 ofprocessing assembly450.Elongated portion482 may include anopening459 at or near one end. Another end ofelongated portion482 may be adjacent to transitionportion480.Transition portion480 may extend fromelongated portion482 to processingportion484.

According to some embodiments,transition portion480 may be bent so as to connectelongated portion482 to processingportion484.Divider483 may be positioned betweenelongated portion482 andprocessing portion484 such thatprocessing portion484 is open toelongated portion482 viatransition portion480.Divider483 may comprise a wall and/or other feature disposed betweenelongated portion482 andprocessing portion484 ofprocessing container452.Superabrasive element10 and afirst volume461 comprisingprocessing agent60 may be disposed withinprocessing portion484 ofprocessing container452.Superabrasive element10 may be positioned and/or secured withinprocessing container452 using any suitable mechanism, without limitation.Processing agent60 may comprise a leaching agent, a cleaning agent, a rinsing agent, and/or any other suitable agent for processing asuperabrasive element10.Cavity458 of theprocessing assembly450 may be open to atmospheric surroundings through anopening459 at the top of theprocessing container452. Asecond volume462 may be disposed withinelongated portion482 andtransition portion480.Second volume462 may comprise a portion ofsecond fluid472 that is disposed gravitationally higher thanfirst volume461 comprisingprocessing agent60. Additionally, atransition volume481 may extend fromsecond volume462 tofirst volume461.Transition volume481 may be adjacent tosecond volume462 atboundary line449 and may be adjacent tofirst volume461 atboundary line447. At least a portion oftransition volume481 may comprisesecond fluid472. Additionally, at least a portion oftransition volume481 adjacent tofirst volume461 may comprise processingagent60.

At least a portion ofsuperabrasive element10 andprocessing agent60 may be exposed to a temperature that is close to or above a phase change temperature ofprocessing agent60 under standard conditions (e.g., standard temperature and pressure). Heating ofprocessing agent60 may be accomplished by any suitable means, such as, for example, resistance-based heating, inductive heating, microwave heating, dielectric heating, and/or combustion source heating, without limitation. Additionally, heating elements may be placed in different positions, such as, for example, withincavity458 ofprocessing container452 and/or within the walls ofprocessing container452. Additionally or alternatively,processing agent60 and/orsuperabrasive element10 may be heated by applying an electric current or field thereto, to any of the walls ofprocessing container452, or apre-heated processing agent60 may be injected intofirst volume461 ofprocessing container452.

As described above, preventing or inhibiting phase change and/or excessive evaporation of processingagent60 may further facilitate leaching and/or cleaning ofsuperabrasive element10 by preventing or inhibiting loss of processingagent60 and/or one or more components ofprocessing agent60 from processingcontainer452.Second fluid462 may be disposed gravitationally above processingagent60 so as to exert a sufficient gravitational body force onfirst volume461 ofprocessing agent60 to prevent or inhibit a phase change and/or excessive evaporation during processing ofsuperabrasive element10.

According to some embodiments,second fluid472 may have a different density (e.g., a greater density) than processingagent60 and may be disposed adjacent tofirst volume461. For example,second fluid472 may comprise a fluid composition that is denser than processingagent60.Second fluid472 may comprise any suitable fluid composition, without limitation.Processing agent60 andsecond fluid472 may comprise separate fluid compositions that are substantially insoluble with respect to each other in order to maintain separation betweenprocessing agent60 andsecond fluid472. In at least one embodiment,second fluid472 may act as an evaporation barrier inhibiting or preventing evaporation of processingagent60.

Processing assembly450 may facilitate the use of asecond fluid472 to exert a gravitational body force onfirst volume461 ofprocessing agent60, particularly whensecond fluid472 is more dense than processingagent60. For example,first volume461 ofprocessing agent60 may be disposed withinprocessing portion484 ofprocessing container452 at a position that is gravitationally above an adjacent portion ofsecond fluid472. Accordingly, while the adjacent portionsecond fluid472 is disposed gravitationally belowfirst volume461 ofprocessing agent60,second fluid472 inelongated portion482 may exert a body force onfirst volume461 ofprocessing agent60 sincesecond fluid472 rises withinelongated portion482 to a height H₅gravitationally abovefirst volume461 disposed inprocessing portion484. The body force may be exerted onfirst volume461 ofprocessing agent60 viasecond fluid472 oftransition volume481 disposed intransition portion480. The body force may be exerted bysecond fluid472 on processingagent60 assecond fluid472 pushes gravitationally upward (i.e., opposite the direction G of gravitational acceleration) against processing agent60 (e.g., atfluid interface486 whensecond fluid472 has a greater density than processing agent60). The gravitational body force exerted on processingagent60 may prevent or inhibit a phase change and/or excessive evaporation of processingagent60 during processing ofsuperabrasive element10. The amount of gravitational body force exerted on theprocessing agent60 under standard conditions (e.g., standard temperature and pressure) may be dependent, at least in part, on the density ofsecond fluid472 and the height H₅ofsecond fluid472 inelongated portion482 ofprocessing container452.

FIG. 11 is a perspective view of anexemplary drill bit42 according to at least one embodiment.Drill bit42 may represent any type or form of earth-boring or drilling tool, including, for example, a rotary drill bit.

As illustrated inFIG. 11,drill bit42 may comprise abit body44 having alongitudinal axis51.Bit body44 may define a leading end structure for drilling into a subterranean formation by rotatingbit body44 aboutlongitudinal axis51 and applying weight tobit body44.Bit body44 may include radially and longitudinally extendingblades46 with leadingfaces48 and a threadedpin connection50 for connectingbit body44 to a drill string.

At least one cuttingelement57 may be coupled tobit body44. For example, as shown inFIG. 11, a plurality of cuttingelements57 may be coupled toblades46.Cutting elements57 may comprise any suitable superabrasive cutting elements, without limitation. In at least one embodiment, cuttingelements57 may be configured according to previously describedsuperabrasive element10 and/orsuperabrasive disc28. For example, each cuttingelement57 may include a superabrasive table65, such as a PCD table, bonded to asubstrate67.

Circumferentiallyadjacent blades46 may define so-calledjunk slots53 therebetween.Junk slots53 may be configured to channel debris, such as rock or formation cuttings, away from cuttingelements57 during drilling.Rotary drill bit42 may also include a plurality ofnozzle cavities55 for communicating drilling fluid from the interior ofrotary drill bit42 to cuttingelements57.

FIG. 11 depicts an example of arotary drill bit42 that employs at least one cuttingelement57 comprising a superabrasive table65 fabricated, structured, or processed in accordance with the disclosed embodiments, without limitation.Rotary drill bit42 may additionally represent any number of earth-boring tools or drilling tools, including, for example, core bits, roller-cone bits, fixed-cutter bits, eccentric bits, bicenter bits, reamers, reamer wings, or any other downhole tool including superabrasive cutting elements and discs, without limitation.

The superabrasive elements and discs disclosed herein may also be utilized in applications other than cutting technology. For example, embodiments of superabrasive elements disclosed herein may also form all or part of heat sinks, wire dies, bearing elements, cutting elements, cutting inserts (e.g., on a roller cone type drill bit), machining inserts, or any other article of manufacture as known in the art. Thus, superabrasive elements and discs, as disclosed herein, may be employed in any suitable article of manufacture that includes a superabrasive element, disc, or layer. Other examples of articles of manufacture that may incorporate superabrasive elements as disclosed herein may be found in U.S. Pat. Nos. 4,811,801; 4,268,276; 4,468,138; 4,738,322; 4,913,247; 5,016,718; 5,092,687; 5,120,327; 5,135,061; 5,154,245; 5,460,233; 5,544,713; and 6,793,681, the disclosure of each of which is incorporated herein, in its entirety, by this reference.

In additional embodiments, a rotor and a stator, such as a rotor and a stator used in a thrust bearing apparatus, may each include at least one superabrasive element according to the embodiments disclosed herein. For an example, U.S. Pat. Nos. 4,410,054; 4,560,014; 5,364,192; 5,368,398; and 5,480,233, the disclosure of each of which is incorporated herein, in its entirety, by this reference, disclose subterranean drilling systems that include bearing apparatuses utilizing superabrasive elements as disclosed herein.

FIG. 12 is partial cross-sectional perspective view of an exemplary thrust-bearingapparatus63 according to at least one embodiment. Thrust-bearingapparatus63 may utilize any of the disclosed superabrasive element embodiments (e.g., superabrasive elements processed according to the instant disclosure) as bearingelements70. Thrust-bearingapparatus63 may also include bearingassemblies66. Each bearingassembly66 may include asupport ring68 fabricated from a material, such as steel, stainless steel, or any other suitable material, without limitation.

Eachsupport ring68 may include a plurality ofrecesses69 configured to receive correspondingbearing elements70. Each bearingelement70 may be mounted to acorresponding support ring68 within a correspondingrecess69 by brazing, welding, press-fitting, using fasteners, or any another suitable mounting technique, without limitation. One or more of bearingelements70 may be configured in accordance with any of the disclosed superabrasive element embodiments. For example, each bearingelement70 may include asubstrate72 and a superabrasive table74 comprising a PCD material. Each superabrasive table74 may form a bearingsurface76.

Bearing surfaces76 of one bearingassembly66 may bear against opposing bearingsurfaces76 of acorresponding bearing assembly66 in thrust-bearingapparatus63, as illustrated inFIG. 12. For example, afirst bearing assembly66 of thrust-bearingapparatus63 may be termed a “rotor.” The rotor may be operably coupled to a rotational shaft. Asecond bearing assembly66 of thrust-bearingapparatus63 may be held substantially stationary relative to thefirst bearing assembly66 and may be termed a “stator.”

FIG. 13 is a partial cross-sectional perspective view of aradial bearing apparatus78 according to another embodiment.Radial bearing apparatus78 may utilize any of the disclosed superabrasive element embodiments (e.g., superabrasive elements processed according to the instant disclosure) as bearingelements84 and86.Radial bearing apparatus78 may include aninner race80 positioned generally within anouter race82.Inner race80 may include a plurality of bearingelements84 affixed thereto, andouter race80 may include a plurality ofcorresponding bearing elements86 affixed thereto. One or more of bearingelements84 and86 may be configured in accordance with any of the superabrasive element embodiments disclosed herein.

Inner race80 may be positioned generally withinouter race82. Thus,inner race80 andouter race82 may be configured such that bearing surfaces85 defined by bearingelements84 and bearingsurfaces87 defined by bearingelements86 may at least partially contact one another and move relative to one another asinner race80 andouter race82 rotate relative to each other. According to various embodiments, thrust-bearingapparatus63 and/orradial bearing apparatus78 may be incorporated into a subterranean drilling system.

FIG. 14 is a partial cross-sectional perspective view of an exemplarysubterranean drilling system88 that includes a thrust-bearingapparatus63, as shown inFIG. 12, according to at least one embodiment.Subterranean drilling system88 may include ahousing90 enclosing a downhole drilling motor92 (i.e., a motor, turbine, or any other suitable device capable of rotating an output shaft, without limitation) that is operably connected to anoutput shaft94.

The thrust-bearingapparatus63 shown inFIG. 12 may be operably coupled todownhole drilling motor92. Arotary drill bit96, such as a rotary drill bit configured to engage a subterranean formation and drill a borehole, may be connected tooutput shaft94. As illustrated inFIG. 14,rotary drill bit96 may be a roller cone bit comprising a plurality ofroller cones98. According to additional embodiments,rotary drill bit96 may comprise any suitable type of rotary drill bit, such as, for example, a so-called fixed-cutter drill bit. As a borehole is drilled usingrotary drill bit96, pipe sections may be connected tosubterranean drilling system88 to form a drill string capable of progressively drilling the borehole to a greater depth within a subterranean formation.

A first thrust-bearingassembly66 in thrust-bearingapparatus63 may be configured as a rotor that is attached tooutput shaft94 and a second thrust-bearingassembly66 in thrust-bearingapparatus63 may be configured as a stator. During a drilling operation usingsubterranean drilling system88, the rotor may rotate in conjunction withoutput shaft94 and the stator may remain substantially stationary relative to the rotor.

According to various embodiments, drilling fluid may be circulated throughdownhole drilling motor92 to generate torque and effect rotation ofoutput shaft94 androtary drill bit96 attached thereto so that a borehole may be drilled. A portion of the drilling fluid may also be used to lubricate opposing bearing surfaces of bearingelements70 on thrust-bearingassemblies66.

FIG. 15 illustrates anexemplary method1500 for processing a polycrystalline diamond material according to at least one embodiment. As shown inFIG. 15, the method for processing a polycrystalline diamond material may include exposing at least a portion of the polycrystalline diamond material to a processing agent for removing at least a portion of an interstitial material from interstitial spaces within the polycrystalline diamond material (step1502).

The polycrystalline diamond material may be exposed to the processing agent in any suitable manner, such as, for example, by submerging at least a portion of the polycrystalline diamond material in the processing agent.

A polycrystalline diamond material may comprise at least a portion of any suitable polycrystalline diamond article. For example, the polycrystalline material may comprise a superabrasive table attached to a tungsten carbide substrate in a superabrasive element or a superabrasive disc (e.g.,superabrasive element10 andsuperabrasive disc28 inFIGS. 1 and 2, respectively). The polycrystalline diamond material may include bonded diamond grains and interstitial regions between the bonded diamond grains (e.g.,grains32 andinterstitial regions34 inFIG. 4). Additionally, the interstitial material may be a metal-solvent catalyst, such as cobalt, nickel, iron, and/or any suitable group VIII element, may be disposed in at least some of the interstitial regions between the bonded diamond grains.

In some embodiments, the processing agent may comprise a leaching agent that removes at least a portion of an interstitial material from the polycrystalline diamond material to form a volume in the polycrystalline diamond material from which an interstitial material has been substantially removed (e.g.,first volume30 inFIG. 3A).

In various embodiments, the volume of processing agent may comprise a cleaning agent for cleaning the polycrystalline diamond material. Generally, such a cleaning agent may be utilized for removing an interstitial material from the polycrystalline diamond material. For example, following leaching, a leaching agent and compounds (e.g., dissolved therein) or other interstitial materials may be removed from a polycrystalline diamond material after a leaching process by exposing at least a portion of the polycrystalline diamond material to a cleaning agent. Such a cleaning agent may include any material suitable for removing the leaching agent and/or other compounds from interstitial spaces within the polycrystalline diamond material. The polycrystalline diamond material may be exposed to the cleaning agent in any suitable manner, such as, for example, by submerging at least a portion of the polycrystalline diamond material in the cleaning agent.

The method may further include applying a body force to the processing agent while at least the portion of the polycrystalline diamond material is exposed to the processing agent (step1504). The body force may be applied to the processing agent in any suitable manner. For example, a centrifugal body force may be exerted on the processing agent as the polycrystalline diamond material and processing agent are rotated at high speed in a centrifuge. Additionally, a gravitational body force may be exerted on processing agent by, for example, a second volume of fluid. The second volume of fluid may comprise, for example, the processing agent and/or another fluid composition having the same or different density than the processing agent.

The method may additionally include heating at least one of the processing agent and at least the portion of polycrystalline diamond material exposed to the processing agent during application of the elevated body force (step1506). At least a portion ofsuperabrasive element10 andprocessing agent60 may exhibit a temperature that is close to, at, below, or above a phase change temperature of theprocessing agent60 under standard conditions (e.g., standard temperature and pressure). According to some embodiments, depending on the type ofprocessing agent60 used,processing agent60 and/orsuperabrasive element10 may be heated to temperatures greater than approximately 50° C. For example,processing agent60 and/orsuperabrasive element10 may be heated to temperatures ranging from approximately 50° C. up to, or in excess of 500° C. (e.g., approximately 60° C., 70° C., 80° C., 90° C., 100° C., 120° C., 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., 210° C., 220° C., 230° C., 240° C., 250° C., 260° C., 270° C., 280° C., 290° C., 300° C., 310° C., 320° C., 330° C., 340° C., 350° C., 360° C., 370° C., 380° C., 390° C., 400° C., 410° C., 420° C., 430° C., 440° C., 450° C., 460° C., 470° C., 480° C., 490° C., 500° C.).

The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments described herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. It is desired that the embodiments described herein be considered in all respects illustrative and not restrictive and that reference be made to the appended claims and their equivalents for determining the scope of the instant disclosure.

Unless otherwise noted, the terms “a” or “an,” as used in the specification and claims, are to be construed as meaning “at least one of.” In addition, for ease of use, the words “including” and “having,” as used in the specification and claims, are interchangeable with and have the same meaning as the word “comprising.”

Claims (22)

What is claimed is:

1. A method of processing a polycrystalline diamond material, the method comprising:

exposing at least a portion of a polycrystalline diamond material to a processing agent for removing at least a portion of an interstitial material;

applying an elevated body force to the processing agent while at least the portion of the polycrystalline diamond material is exposed to the processing agent, the body force comprising at least one of a gravitational body force and a centrifugal body force;

heating at least one of the processing agent and at least the portion of the polycrystalline diamond material exposed to the processing agent during application of the elevated body force.

2. The method ofclaim 1, wherein the processing agent comprises a leaching agent for leaching a metallic material from interstitial spaces within at least the portion of the polycrystalline diamond material.

3. The method ofclaim 1, wherein the processing agent comprises a cleaning agent for cleaning at least the portion of the polycrystalline diamond material.

4. The method ofclaim 1, wherein:

the processing agent comprises a liquid solution;

the elevated body force is sufficient to prevent a phase change of the liquid solution during heating.

5. The assembly ofclaim 1, wherein the heating comprises a heating to a temperature greater than a temperature required for a phase change of the liquid solution under atmospheric conditions.

6. The method ofclaim 1, wherein applying the elevated body force comprises rotating the processing agent and the polycrystalline diamond material about a rotational axis.

7. The method ofclaim 1, wherein applying the elevated body force comprises disposing another fluid gravitationally above the processing agent.

8. The method ofclaim 7, wherein the other fluid has a density greater than the density of the processing agent.

9. The method ofclaim 7, wherein:

the polycrystalline diamond material, the processing agent, and the other fluid are disposed within a container;

the other fluid has a height within the container greater than a height of the processing agent within the container.

10. The method ofclaim 7, wherein the other fluid contacts the processing agent.

11. The method ofclaim 7, wherein the other fluid is open to atmospheric surroundings.

12. The method ofclaim 1, further comprising disposing a protective barrier around a portion of the polycrystalline diamond material.

13. The method ofclaim 1, wherein the polycrystalline diamond material comprises a polycrystalline diamond body bonded to a substrate.

14. An assembly for processing a polycrystalline diamond body, the assembly comprising:

a processing container;

at least one polycrystalline diamond body disposed in the processing container;

a volume of processing agent disposed in the processing container, at least a portion of the polycrystalline diamond body being exposed to the processing agent, the processing agent processing at least a portion of the polycrystalline diamond body;

a body force application portion for applying an elevated body force to the processing agent while at least the portion of the polycrystalline diamond body is exposed to the processing agent, the body force comprising at least one of a gravitational body force and a centrifugal body force;

a heating element for increasing a temperature of at least one of the processing agent and at least the portion of the polycrystalline diamond body exposed to the processing agent during application of the elevated body force to the processing agent.

15. The assembly ofclaim 14, wherein:

the processing agent comprises a liquid solution;

the elevated body force is sufficient to prevent a phase change of the liquid solution during heating.

16. The assembly ofclaim 14, wherein the body force application portion comprises a centrifugal device for rotating the processing container about a rotational axis.

17. The assembly ofclaim 14, wherein the body force application portion comprises a fluid conduit containing another fluid disposed gravitationally above the processing agent.

18. The assembly ofclaim 17, wherein the fluid conduit extends in a vertical direction.

19. The assembly ofclaim 17, wherein the other fluid has a density greater than the density of the processing agent.

20. The assembly ofclaim 17, wherein the other fluid has a height within the fluid conduit greater than a height of the processing agent within the fluid conduit.

21. The assembly ofclaim 17, wherein an end of the fluid conduit disposed apart from the processing container comprises an opening such that the other fluid is open to atmospheric surroundings.

22. The assembly ofclaim 14, further comprising a protective barrier disposed around a portion of the polycrystalline diamond body.

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